1. Field of Invention
The present invention relates to a semiconductor device, a display device and a method for manufacturing thereof, and a television device.
2. Description of the Related Art
A thin film transistor (hereinafter also referred to as a “TFT”) and an electric circuit using the thin film transistor are formed by stacking various kinds of thin films such as a semiconductor, an insulator and a conductor over a substrate, and appropriately patterning into a predetermined shape using photolithography technique. Photolithography technique is a technique in which a pattern of a circuit or the like, which is formed on a transparent plane plate called a photomask using a non-light-transmitting material, is transferred to an intended substrate by utilizing light. The photolithography technique is widely used in a process of manufacturing a semiconductor integrated circuit, and the like.
The conventional manufacturing process using photolithography technique requires multiple steps such as exposure, development, baking and peeling only for treating a mask pattern, which is formed by using a photosensitive organic resin material which is referred to as a photoresist. Therefore, the manufacturing cost is inevitably increased with the increase of the number of photolithography steps. In order to solve this problem, it has been attempted to manufacture TFTs by reducing the number of photolithography steps (For example, Japanese Patent Application Laid-Open No. H 11-251259).